Dismiss any active bubbles when the channel setting is disabled

This change routes a callback to BubbleController to notify when the
bubble setting of a channel is disabed. In response, any active bubbles
associated with notifications in that channel will be dismissed.

Test: add a bubble, disable bubble on channel settings
Bug: 130441629
Change-Id: Iba20051c4eadebfda949fa7a6f73042c05358c93